The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Dry Mouth on Mounjaro — What You Need to Know
Dry mouth is one of the more common side effects reported by people using Mounjaro (tirzepatide) in the UK. While it's not typically serious, understanding why it occurs and how to manage it can help you stay comfortable during treatment. This guide explains the causes, management strategies, and when to seek advice from your GP.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Why Does Mounjaro Cause Dry Mouth?
Dry mouth on Mounjaro occurs for several interconnected reasons. First, GIP and GLP-1 receptor agonists like tirzepatide slow gastric emptying—how quickly food leaves your stomach—which can reduce overall saliva production. Second, Mounjaro may reduce appetite and food intake, and eating stimulates saliva flow naturally. Third, some people experience nausea or reduced interest in food, which further decreases the signals that trigger saliva production. Additionally, the medication may directly affect salivary gland function through its receptor pathways. Dehydration can also worsen dry mouth, particularly if nausea or vomiting occurs. Unlike some Mounjaro side effects that improve as your body adjusts during dose titration, dry mouth may persist throughout treatment. It's worth noting that individual experiences vary significantly—some people on the same Mounjaro dose report no dry mouth at all, whilst others find it bothersome.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
Managing Dry Mouth — Practical Strategies
Hydration is key: Drink water regularly throughout the day, even if you don't feel thirsty. Keep a water bottle with you and sip frequently. Sugar-free drinks like herbal tea (hot or cold) can also help. Avoid caffeine and alcohol, which are dehydrating.
- Use sugar-free lozenges or chewing gum to stimulate saliva production
- Apply lip balm regularly to prevent cracking
- Use a humidifier in your bedroom at night to add moisture to the air
- Eat soft, moist foods when you do eat—soups, smoothies, and fruits with high water content
- Rinse your mouth with water after meals to maintain oral health
If dry mouth persists or becomes severe, contact your GP. Persistent dry mouth can occasionally lead to oral infections or dental problems, so professional guidance is important.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Is dry mouth a sign that Mounjaro isn't working?
No. Dry mouth is a side effect unrelated to how well Mounjaro is helping with weight management. Many people experience dry mouth whilst still achieving positive weight loss results. It's a separate physiological response to how the medication affects saliva production and appetite.
Does dry mouth improve as you continue Mounjaro treatment?
Dry mouth may improve slightly as your body adjusts, but some people experience it persistently throughout treatment. Unlike nausea, which often reduces during dose titration, dry mouth doesn't always follow the same pattern. If it remains bothersome after several weeks, discuss it with your GP or prescriber.
Can I take anything to help with dry mouth whilst on Mounjaro?
Yes. Sugar-free lozenges, chewing gum, and mouthwash designed for dry mouth are safe options. Stay well hydrated by drinking water regularly. Avoid alcohol and excessive caffeine. If you're concerned about any over-the-counter products, ask your prescriber or pharmacist—they can confirm what's safe alongside your Mounjaro treatment.
When should I contact my GP about dry mouth on Mounjaro?
Contact your GP if dry mouth is severe, persistent, or affecting your quality of life significantly. Also seek advice if you notice signs of oral infection, difficulty eating, or dental problems developing. Your GP can assess whether it's medication-related or if there's another underlying cause.
Does dry mouth happen at all Mounjaro doses?
Dry mouth can occur at any Mounjaro dose, from the starting 2.5 mg through to the 15 mg maintenance dose. It's not necessarily dose-dependent—some people report it at lower doses, others at higher doses. Individual variation is significant, and there's no clear pattern across the population.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.